Understanding the Influences Understanding the Influences on the Association between on the Association between
Nurse Staffing and Nurse Staffing and Preventable Patient Preventable Patient
ComplicationsComplications
Deborah Dang, PhD, RNDeborah Dang, PhD, RN2007 Interdisciplinary Research Interest Group2007 Interdisciplinary Research Interest Group
on Nursing Issueson Nursing IssuesAcademy HealthAcademy Health
June 2, 2007June 2, 2007
Problem and SignificanceProblem and SignificanceNurse staffing may be necessary, but Nurse staffing may be necessary, but not sufficient, to prevent adverse not sufficient, to prevent adverse patient eventspatient events
Few studies have examined Few studies have examined characteristics of the work characteristics of the work environment at the unit level that environment at the unit level that may affect staffing may affect staffing
Nurse staffing and characteristics of Nurse staffing and characteristics of the work environment are modifiable the work environment are modifiable features in hospitalsfeatures in hospitals
PurposePurpose
Examine the impact of nurse staffing Examine the impact of nurse staffing and and
potential confounders on preventable potential confounders on preventable
adverse events at the unit level over adverse events at the unit level over a a
seven year period.seven year period.
Research QuestionsResearch Questions
1.1. Is unit-level nurse staffing associated with Is unit-level nurse staffing associated with the failure to rescue, falls, and the failure to rescue, falls, and medication errors between 1998 and medication errors between 1998 and 2004?2004?
2.2. Do unit characteristics confound the Do unit characteristics confound the relationship between nurse staffing and relationship between nurse staffing and adverse events between 1998 and 2004?adverse events between 1998 and 2004?
Central line-associated BSIsCentral line-associated BSIs ++++
Decubitus ulcerDecubitus ulcer ++
FallsFalls ++
Failure to rescueFailure to rescue ++++
Medication errorsMedication errors ++
MortalityMortality ++
Pneumonia, hospital acquiredPneumonia, hospital acquired ++
Pneumonia, vent-associatedPneumonia, vent-associated ++
Post-op PE/DVTPost-op PE/DVT ++
Post-op respiratory failurePost-op respiratory failure ++
UTI, catheter-associatedUTI, catheter-associated ++++
Staffing and Staffing and Strength Strength of of Patient Outcomes Patient Outcomes EvidenceEvidence
++ consistent evidence; + mixed evidence
Conceptual ModelConceptual Model
System
OutcomeIntervention
Client
Quality Health Outcomes Model(Mitchell, Freketich, & Jennings, 1998)
Study ModelStudy Model
System Unit
Nurse Staffing Characteristics•Total hours Agency proportion• RN hours Orientee proportion• RN Proportion RN education• RN shortfall RN experience
RN turnover Patient turnover
OutcomesAdverse Events• Failure to rescue• Falls• Medication errors
Research DesignResearch DesignDesignDesignDescriptive correlational using secondary dataDescriptive correlational using secondary data
SettingSetting945 bed, Magnet-designated, not-for-profit, urban 945 bed, Magnet-designated, not-for-profit, urban
academic medical centeracademic medical center
SampleSampleConvenience sample of 31 adult and pediatric Convenience sample of 31 adult and pediatric
inpatient unitsinpatient units
Unit of analysisUnit of analysisCare-giving unitCare-giving unit
Type of Patients and Level of Type of Patients and Level of CareCare
Adult units: 25 (84%)Adult units: 25 (84%)
Acute care: 16 (52%)Acute care: 16 (52%)
IMC: 8 (26%)IMC: 8 (26%)
ICU: 7 (23%)ICU: 7 (23%)
* > 100% due to rounding* > 100% due to rounding
File DevelopmentFile Development
Design and construct the database and Design and construct the database and merge proceduresmerge procedures
Restructure databaseRestructure database
Develop procedures for handling:Develop procedures for handling: Changes in cost centersChanges in cost centersInconsistent reporting periodsInconsistent reporting periodsHandling missing dataHandling missing data
Construct 3 separate files for analyses:Construct 3 separate files for analyses:Failure to rescue (N = 28)Failure to rescue (N = 28)Falls (n=560)Falls (n=560)Medication errors (n = 341)Medication errors (n = 341)
AnalysesAnalyses
Hospital-level: Failure to RescueHospital-level: Failure to Rescue– DescriptiveDescriptive– Bivariate: zero-order and first-order Bivariate: zero-order and first-order
correlationscorrelations
Unit-level: Falls and Medication errorsUnit-level: Falls and Medication errors– Poisson regression with a robust variance Poisson regression with a robust variance
estimatorestimator– Adjust for type of unitAdjust for type of unit– Account for change in AE rates over time by Account for change in AE rates over time by
including a quadratic function of timeincluding a quadratic function of time
Sample BenchmarksSample Benchmarks
Total HPPDTotal HPPD RN Proportion RN Proportion (%)(%)
AcutAcutee
IMCIMC ICUICU AcutAcutee
IMCIMC ICUICU
Current Current studystudy(31 units)(31 units)
8.78.7 12.712.7 21.521.5 81.581.5 83.783.7 87.587.5
Dunton Dunton (1751 (1751 units)units)
7.6*7.6* 9.1*9.1* 15.9*15.9* 63.663.6 69.769.7 89.289.2
BlegenBlegen(39 units)(39 units)
8.68.6 18.018.0 69.069.0 90.090.0*Median
Unit CharacteristicsUnit Characteristics Overall Overall MeanMean
Agency proportion, %Agency proportion, % 10.0610.06
Orientation proportion, %Orientation proportion, % 5.045.04
RN education, % BSNRN education, % BSN 77.6677.66
RN experience, yearsRN experience, years 7.777.77
RN turnover, %RN turnover, % 9.329.32
Patient turnover, ADT*Patient turnover, ADT* 9.129.12
*admissions, discharges, transfers
Correlation: FTR and Correlation: FTR and StaffingStaffing
Zero-order CorrelationZero-order Correlation RR22
Total hoursTotal hours -.795**-.795** .63.63
RN hoursRN hours -.797**-.797** .64.64
RN proportionRN proportion -.085 -.085 .01.01
RN shortfallRN shortfall .678**.678** .46.46
*p < .05, **p < .01
First-order CorrelationFirst-order Correlation
FTR and StaffingFTR and Staffing
Removing:Removing:
Zero-Zero-orderorder
CorrelatioCorrelationn
Agency Agency ProportionProportion
RN RN TurnoverTurnover
Total hoursTotal hours(R(R22))
-.795**-.795**(.63)(.63)
-.756**-.756**(.57)(.57)
-.762**-.762**(.58)(.58)
RN hoursRN hours(R(R22))
-.797**-.797**(.64)(.64)
-.757**-.757**(.57)(.57)
-.767**-.767**(.59)(.59)
RN shortfallRN shortfall(R(R22))
.678**.678**(.46)(.46)
-.679**-.679**(.46)(.46)
.654**.654**(.43)(.43)
Relative Rate of Falls for each 10% Relative Rate of Falls for each 10% Increase in StaffingIncrease in Staffing
Unadjusted and Adjusted Relative Rates
Rate of Medication Errors by Type of UnitRate of Medication Errors by Type of Unit (n (n = 341)= 341)
Relative Rate of Medication Errors for each Relative Rate of Medication Errors for each 10% increase in Staffing10% increase in Staffing
Unadjusted and Adjusted Relative Rates
Summary of FindingsSummary of Findings
Staffing effect found for all AEsStaffing effect found for all AEs
RN shortfall effect found for FTR and fallsRN shortfall effect found for FTR and falls
Unit characteristics had little to no Unit characteristics had little to no influence on association between staffing influence on association between staffing and AEsand AEs
Unclear explanation for findings in Unclear explanation for findings in unexpected directionunexpected direction
LimitationsLimitations
Measurement errorMeasurement error
Risk adjustment for falls and Risk adjustment for falls and medication errorsmedication errors
Other unmeasured factorsOther unmeasured factors
GeneralizabilityGeneralizability
Implications for PracticeImplications for Practice
Longitudinal data presented Longitudinal data presented opportunity to explore multiple opportunity to explore multiple predictors at the unit levelpredictors at the unit level
Investment needed by hospitals to Investment needed by hospitals to collect and monitor unit-level datacollect and monitor unit-level data
Unique conceptualization and Unique conceptualization and measurement of staffingmeasurement of staffing
Future ResearchFuture Research
Unit-level risk adjustments methodsUnit-level risk adjustments methods
Large scale unit-level studiesLarge scale unit-level studies
Attribution of failure to rescue to Attribution of failure to rescue to unit-levelunit-level
Impact of organizational factors on Impact of organizational factors on staffing and patient outcomesstaffing and patient outcomes